Connecter plug



Nov. 21, 1933. s GUINN 1,936,014

CONNECTER PLUG Filed July '15, 1932 Patented Nov. 21, 1933 1,936,014

UNi'iED STATES PATENT OFFICE CONNECTER PLUG Samuel E. Guinn, Johnson City, Tenn., assignor to G. A. Bowman, Annapolis Junction, Md.

Application July 15, 1932. Serial No. 622,766

2 Claims. (01. 20051) This invention is directed to an improvement width providing projections 7 to afi'ord a finger in connecting plugs for electric appliances, such grip in handling the plug. as irons or the like, wherein the plug has one The bottom section 2 of the plug is formed in end formed to snugly seat in a guard cover surits uppermost face, or that face with which the rounding the terminals of the heating circuit in cover section 3 cooperates, with a rectangular 60 the iron or the like, with the plug having sockets depression 8 within the enlarged area 5 of such to slidably and irictionally fit over said terminals. section. The section 2 in that portion included Plugs of this type are subjected to hard usage within the part 4 of the plug is formed with and frequently become broken due to weakness in spaced, longitudinal depressions 9 opening at 10 structure, this liability to breakage being partheir rear ends through the end of the plug and 65 ticularly incident to plugs of this type which in communicating with the central depression 8 at addition to their connecting feature involve the their forward ends. In'advance of the depresuse or" a switch by which the circuit may be consion 8, the section 2 is cut away at 10 to leave trolled directly at the appliance. a bottom wall 11 somewhat higher than the The primary object of the present invention bottom wall of the depression 8. The section 2 70 is the provision of a plug of this type made in in advance of the wall 11 has a semi-annular sections, as is usual, with particular meansior channel 12, and at the forward end of the plug, confining the sections in plug-forming relation 1. e. in advance of the channel 12, the section 2 to maintain extreme rigidity of the parts and is formed with a semi-circular depression 13 prevent liability of breakage incident to extreme opening through the forward end, the diameter 75 usage of the plug. of the depression 13 being less than the diameter A further object of the invention is the arof the annular channel 12. rangeinent of the interior parts of the plug to The section 3 is formed with substantially insure their effective operation and insure their complementary parts, i. e. in the face next the complete and efiective insulation against breaksection 2 the rear end of the section 3, i. e. the age during the use of the plug. portion inclded within the part 4 of the plug, has The invention is illustrated in the accompanyslight rounded depressions which register with ing drawing, in which: the channels 9 of the section 2 and form there- Figure 1 is a perspective view of the improved with circular channels. In advance of the deplug. pressions 4 the section 3 is formed with a rec- Figure 2 is a longitudinal section, partly in tangular depression 15 corresponding to and elevation, of the same. overlying the depression 8 and forming with the Figure 3 a plan of the plug with the upper latter an interior rectangular chamber in which body section removed. the switch operating parts are mounted, will Fig. l is a detail view of a switch employed in later appear. The section 3 is also formed with 9 the plug. an annular, semi-circular depression 16 regis- Fig. 5 is a detail view of a contact strip with tering with and forming with the channel 12 which the switch cooperates. an annular channel when the sections 2 and 3 are The plug as a whole is, as is usual in plugs of assembled. this type, of relatively flat form, i. e. the plug body In advance of the depression 16, the section 1 has a greater width than thickness. This body 3 is formed with a semi-circular opening 17 comis divided longitudinally to present a lower secplementary to the opening 13 of the section 2 and tion 2 and an upper section 3, the lower section forming therewith a central aperture leading being designed to carry the circuiting detail and into the interior of the plug. The abutments 45 the upper section serving largely as a cover secformed by the surfaces 11 of the section 3 are dition, vided by a longitudinal channel 18 extending cen- The sections are of course of insulating matrally and longitudinally of the plug and leading -terial and for the particular purpose contemplatto the opening at the forward end. The abuted are formed to present an instrument engaging ments 11 on each side of this channel are formed 50 end 4. constituting the narrowest and thinnest withwire-receiving depressions 19 extending in portion of the plug, a central portion 5 which opposite directions and leading to the interior is of increased thickness and width as compared conductors 20 arranged at each side of the secwith the section a, and a cord terminal engaging tion 2 of the plug. These conductors 20 which end or section 6 which is substantially of the are, of course, metallic have a terminal 21 over- 5 same thickness as the section 5 but of increased lying the bottom 11 of the abutment and secured 1 thereto by a screw 22 serving as a binding screw. From the terminal section 11, the conductors 20 are bent downwardly, as at 23, to overlie end wall of the depression 8 and then longitudinally, as at 24, to bear against the bottom of said depression. The outer edge of the portion 24 is formed near the free end thereof with an upturned ear 25.

Arranged within the circular channels formed by the depressions 9 and 14 are contact sleeves 26 which terminate short of the free ends of the channels and may, if desired, be split longitudinally to insure proper frictional engagement and therefore good contact with the usual plugs of the implement. These contact sleeves extend forwardly of the channels in which they are housed and have split spring ends 27 for switch cooperation. Switch elements 28 are pivotally connected to the ears 5 of the respective conducting strips 20. These switch elements have rearwardly extending knife edge projections 29 designed, when the elements are rocked in one direction, to engage in the split spring terminals 27 of the contact sleeves 26. The switch elements have their upper ends 30 rigidly connected to an insulating block 31, the upper end of which is extended in two directions to provide an indicating surface 32, with the indicating surface centrally provided with an upstanding finger piece 33. The depression 15 in the sec tion 3 of the switch body opens through the upper surface of such section, thereby forming an opening 34 through which the insulating switch block 31, or more particularly the rounded section 32 thereof, together with the finger piece may project in operation. The opening 34 is so formed that in one orithe other position of the switch block and switching elements, only one of the surfaces of the section 32 on opposite sides of the finger piece 33 is exposed, and these surfaces are appropriately marked Off and On to indicate the condition of the switch. The interior formation of the section 3 in advance of the recess 15 is formed to receive the forward portion of the head 32 of the switch block when the switch has been operated to break the circuit, while the rear edge of the opening 34 is formed with a projection 35 to limit the position of the switch.

The annular channel formed by the depressions 12 and 16 in the respective sections receives the annular enlargement 36 at the terminal of the usual flexible element 37 through which conductor wir s are led and which serves to prevent kinking of the wires adjacent the plug. The formation of the channels 9 in the section 2 leave a longitudinally ranging plane section 38 which abuts against the face of section 3, and these portions of the respective sections are formed, one with a pin 39, and the other with an opening 40 to accurately align the ends of the sections when placing them together.

An important detail of the present invention resides in the means for holding the sections of the plug together and protecting the plug to a material extent against breakage under hard usage. For this purpose, that portion of the plug sections making up the terminal portion of the plug are encircled by a tight fitting metallic band il. This band completely encircles the body at this point, insures that the sections are held in accurate and fixed relation, and yet protects the plug against breakage which often occurs in inserting the plug or withdrawing it or from dropping the plug onto a hard surface. The opposite end of each section is formed with a reduced, semi-annular projection 42 which directly encircles the depressions l3 and 17 forming the central entrance to the plug. These projections 42, when the plug sections are assembled, form a circular member at the forward end of the plug and the peripheral surface of this member is formed with a channel 43, in which is secured a split spring ring 44. The ring serves to hold the sections fixedly together against separation and relative displacement at the forward end.

The conductor wires are, of course, extended through the protector 3'7 and then laterally through the depressions 19 and about the screws 22 of the respective conductors, so that operation of the switch member will make or break the continuity of the circuit to the implement.

If desired, and as preferred, the ears 25 and the cooperating parts of the switch elements 28 may be formed with depressions and projections, indicated at 45, to prevent casual displacement of the parts in either closed or opened switching relation.

I claim:-

1. A connecter plug comprising a body including an upper and a lower section, the lower section being formed with a central depression, circular depressions at one side of the central depression and communicating at one end with the latter, abutments provided therein in the opposite direction, contact strips overlying the abutments and seating in the depression, said contact strips having ears, contact sleeves arranged in the circular depressions and extending into the central depression as a split section, knife contacts pivoted between the ears on the contact strips and engaging said split sections of the sleeve, and an insulated bar connecting the knife contacts, said insulated bar having a finger piece extending through an opening in the upper section.

2. A connecter plug formed of two sections, one of said sections having a central depression, an abutment in advance of the depression, circular channels at one side of the central depression and communicating at one end with the latter, sleeve contacts arranged in the circular channels and having split spring ends extending into said depression, contact strips secured to the abutments and having portions resting on the bottom of the depression, and formed with ears, knife .contacts pivoted to said contact strips, and an insulated bar connecting the knife contacts, said insulated bar having a finger piece extending through an opening in the upper section, the finger piece having oppositely disposed lateral extensions, the upper section having abutments adjacent the opening walls, engaged by the lateral extensions on the finger piece to limit the movement of the knife contacts, each ection being formed at one end with a semi-circular depression, the said depressions together constituting an annular channel to receive the enlarged end of a conductor protector extending beyond the 

